Railway-traffic-controlling apparatus



April 30, 1929. o. GRONDAHL 1,711,384

RAILWAY TRAFFIC CONTROLLINQ APPARATUS Filed March 19, 1927 A 0/2 3 Tldlh 0 1 I ZPV z 1L 3 f Track m fig RE Way 4, 4a my]. Fig.2

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Patented Apr. 30, 1929 UNITED STATES PATENT OFFICE.

LABS 0. GRONDAHL, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY -TRAFFIG-GONTROLIJING APPARATUS.

Application filed March 19, 1927. Serial No. 176,640.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of the type comprising ,train-carried governing means automatically controlled from the trackway. One feature of my present invention .is the provision of means for capacity coupling between the apparatus on the train and the apparatus in the trackway.

I will describe several forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammaticview showing one form of apparatus embodying my invention. Fig. 2 is a diagrammatic view showing a modifica-.

tion of the trackway apparatus shown in Fig. 1 and also embodying my invention.

Fig.3 is a diagrammatic view showing a modified form of coupling between the traincarried apparatus and the trackway apparatus of Fig. 1 and also embodying my invention.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the train-carried apparatus comprising a circuit including a generator Hof alternating current and a relay C normally energized by the current from the generator H. As here shown, the relay C is of the direct current type, and a full wave rectifier A is interposed between the generator and thejrelay, although this particular type'of relay and means for energizing it from the generator H are not essential to my invention. The relay G controls train governing means of any suitable type, such for example as a brake application valve designated by the reference character EPV. As here shown, this valve is provided with a circuitwhich includes a front contact 2 of the relay C, and which circuit extends between terminals B and O of a suitable source of current.

' The reference character 5 designates a condenser plate which is connected with a train-carried circuit on one side of the relay G, and the reference character 5 designates I -way are two condenser plates 6- and 6 which are arranged to register with, but to be spaced from, the train-carried condenser plates 5 and 5 The trackway plates 6 and 6 are connected by a partial trackway circuit including a reactor 3 and aback contact 4- of a relay R which may be-controlled in any suitable manner, such as by. trafiic conditions in advance. At the frequency of generator H, the inductivereactance of reactor 3 is substantially equal to the capacity reactance of the condensers made up of plates 5-6 and 56.

I will first assume that whenthe train passes the trackway condenser plates, relay R is energized so that contact 4 is open. The partial tra-ckway circuit is then incomplete and the trackway apparatus has no effect on the train-carried apparatus, so that relay C remains closed. If track relay R is de-energized, however, so that its back contact 4 is closed, the trackway partial circuit acting through the condensers 5--6" and 56 shunts enough energy from the relay C to cause this relay to open, because the shunt around relay G is substantially resonant and so its impedance is very low.

reactance of the condensers 5-6 and 5--'6*.

If contact a is closed, however, reactor 3 is shunted by a path of low reactance, so that the path in shunt to relay C is not resonant shown in this view is similar to that shown in Fig. 1, except that-one side of the traincarried circuit is connected with ground G, as, for example, by connecting it with the frame or an axle of the locomotive, while the other side of the train-carried circuit is connected with the plate 5 as in Fig. 1. The traclrway apparatus comprises a partial circuit one terminal of which is connected with ground at G, which will usually be a track rail, and the other terminal of which is connected with a condenser plate 6, so located as to register with the condenser plate 5 on the train. In the form shown inFig. 3, the reactor, which is here designated 3 has an inductive reactance equal to the capacity reactance of the condenser 5 6 at the frequency of generator l-l, so that it contact 4 is closed relay C will be shunted by a path of low impedance with the result that this relay will open. W hen contact 4; is open, the trackway apparatus has no effect on the train-carried apparatus.

Although I have herein shown and described only a few forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traffic controlling apparatus comprising a train carried circuit including a source of alternating current and a relay, two condenser plates connected with said circuit on opposite sides of said relay, two condenser plates located in the trackway to register with said two train carried plates respectively, means for at times electrically connecting said trackway plates, and governing means on the train controlled by said relay.

2. Railway traliic controlling apparatus comprising a train carried circuit including a source of alternating current and a relay, two condenser plates connected with said circuit on opposite sides of said relay, two condenser plates located in the trac'kway to register with said two train carried plates respectively, a partial circuit conerning means on the train controlled by said relay.

Railway traliic controlling apparatus comprising a train carried circuit including a source of alternating current and a relay, two condenser plates connected with said circuit on opposite sides of said relay, two condenser plates located in the trackway to register with said two train carried plates respectively, a partial circuit connecting said two trackWa-y plates and including a reactor, a second partial circuit connecting said trackway plates and including a contact, and governing means on said train controlled by said relay.

4. Railway traffic controlling apparatus comprising a train carried circuit including a source of alternating current and a direct current relay, a full wave rectifier interposed between said source and said relay,

two condenser plates connected with said circuit on opposite sides of said rectifier, two condenser plates located in the trackway to register with said two train carried plates respectively, means for at times electrically connecting said trackway plates, and governing means on the train cointrolled by said relay.

5. Railway trafiic controlling apparatus comprising a train carried circuit including a source of alternating current and a relay normally energized from said source, a par tial circuit located in the trackway and including a contact, means including condenser plates for coupling said train carried and trackway circuits so as to shunt enough energy from said relay to open the relay when the contact in the traclrway circuit is closed, and governing means on the train controlled by said relay.

6. Railway trailic controlling apparatus comprising a train carried circuit including a source of alternating current and a relay normally energized from said'source, a partial circuit located in the trackway, capacity means for coupling said train carried circuit and said trackway partial circuit to shunt enough energy from said relay to open the relay, cont-rolling means included in said partial trackway circuit for rendering said partial circuit ineffective to open said relay, and governing means on the train controlled by said relay.

T'Raflway trailic controlling apparatus comprising a train carried circuit including a source oi": alternating current and a relay normally energized from said source, a shunt around said relay including a partial traclrway circuit containing a reactor, means including condenser plates for coupling said train carried circuit and said partial trackway circuit, the inductive reactance of said reactor being substantially controlling means associated with said trackway partial circuit, and governing means on the train controlled by said relay.

8. Railway traliic controlling apparatus 5? comprising a train carried circuit including I a source of alternating current and a relay normally energized from said source, a shunt around said relay substantlally resonant at the frequency of said source and including a partial trackway element cou- 10 pled with the train carried circuit at least in part by condenser plates, and governing means on the train controlled by said relay. In testimony whereof I afiix my signature.

LABS O. GRONDAHL. 

